Display device and method for manufacturing display device

ABSTRACT

According to one embodiment, a display device includes a display panel including a first substrate, and a wiring board mounted on a mounting portion of the first substrate. The display panel includes a first terminal and a second terminal located in the mounting portion, a first alignment mark located in the mounting portion and located between the first terminal and the second terminal, a first wiring line connected to the first terminal, and a second wiring line connected to the second terminal. The wiring board includes a first connection wiring line connected to the first terminal, a second connection wiring line connected to the second terminal, and a second alignment mark located between the first connection wiring line and the second connection wiring line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of PCT Application No.PCT/JP2019/037377, filed Sep. 24, 2019 and based upon and claiming thebenefit of priority from Japanese Patent Application No. 2018-178968,filed Sep. 25, 2018, the entire contents of all of which areincorporated herein by reference.

FIELD

Embodiments described herein relate generally to a display device and amethod for manufacturing a display device.

BACKGROUND

Recently, demand for display devices for mobile electronic devices andthe like has been increasing. As the display device, a structureincluding a display panel and a wiring board mounted on the displaypanel is known. It is also known that a driving circuit for driving thedisplay panel is mounted on the wiring board. In this structure, adriving signal output from the driving circuit is supplied to thedisplay panel via wiring lines of the wiring board.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration showing the configuration and the equivalentcircuit of a display device of the present embodiment.

FIG. 2 is a cross-sectional view of a display area of a display panelshown in FIG. 1.

FIG. 3 is a plan view showing a mounting portion of the display panel.

FIG. 4 is a plan view showing a part of a wiring board.

FIG. 5 is a plan view showing a state where the wiring board shown inFIG. 4 is mounted on the mounting portion shown in FIG. 3.

FIG. 6 is a cross-sectional view of the display device along a signalwiring line and a connection wiring line shown in FIG. 5.

FIG. 7 is a cross-sectional view of a process of mounting the wiringboard on the display panel.

FIG. 8 is a plan view showing the wiring board and a suction deviceshown in FIG. 7.

FIG. 9 is a cross-sectional view showing the wiring board and thesuction device along line A-B shown in FIG. 8.

FIG. 10 is a plan view showing a comparison on the mounting portionbetween a comparative example and the present embodiment.

FIG. 11 is a plan view showing a comparison on the width of thenon-display area in accordance with a change of the width of the wiringboard.

FIG. 12 is a plan view showing the first modification example of thepresent embodiment.

FIG. 13 is a plan view showing the second modification example of thepresent embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, there is provided a displaydevice comprising: a display panel comprising a first substrate; and awiring board mounted on a mounting portion of the first substrate. Thedisplay panel comprises a first terminal and a second terminal locatedin the mounting portion, a first alignment mark located in the mountingportion and located between the first terminal and the second terminal,a first wiring line connected to the first terminal, and a second wiringline connected to the second terminal. The wiring board comprises afirst connection wiring line connected to the first terminal, a secondconnection wiring line connected to the second terminal, and a secondalignment mark located between the first connection wiring line and thesecond connection wiring line.

According to another embodiment, there is provided a method formanufacturing a display device comprising: a display panel comprising afirst substrate; and a wiring board mounted on a mounting portion of thefirst substrate, wherein the display panel comprises a first terminaland a second terminal located in the mounting portion, a first alignmentmark located in the mounting portion and located between the firstterminal and the second terminal, a first wiring line connected to thefirst terminal, and a second wiring line connected to the secondterminal, and the wiring board comprises a first connection wiring lineconnected to the first terminal, a second connection wiring lineconnected to the second terminal, and a second alignment mark locatedbetween the first connection wiring line and the second connectionwiring line. The method comprises: sucking the wiring substrate by asuction device comprising a first suction port and a second suctionport, wherein the suction device sucks the wiring substrate such thatthe first suction port is positioned overlapping the first connectionwiring line, the second suction port is positioned overlapping thesecond connection wiring line, and both sides of the second alignmentmark are sucked; aligning the display panel and the wiring board by thefirst alignment mark and the second alignment mark; and connecting thefirst terminal and the first connection wiring line together and thesecond terminal and the second connection wiring line together by ananisotropic conductive film.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is merely an example, and properchanges in keeping with the spirit of the invention, which are easilyconceivable by a person of ordinary skill in the art, come within thescope of the invention as a matter of course. In addition, in somecases, in order to make the description clearer, the widths,thicknesses, shapes and the like, of the respective parts areillustrated schematically in the drawings, rather than as an accuraterepresentation of what is implemented. However, such schematicillustration is merely exemplary, and in no way restricts theinterpretation of the invention. In addition, in the specification anddrawings, constituent elements which function in the same or a similarmanner to those described in connection with preceding drawings aredenoted by the same reference numbers, and detailed description of themis omitted unless necessary.

The main configuration of the present embodiment can be used for anelectronic device comprising a flexible wiring board such as a displaydevice. In the present specification, the configuration of the presentembodiment will be described by taking a display device as an example.This display device can be used for various devices such as asmartphone, a tablet computer, a portable telephone, a notebookcomputer, an in-car device and a game console. In addition, the presentembodiment can be applied to various display devices such as a liquidcrystal display device, a self-luminous display device such as anorganic electroluminescent display device, a micro-LED display device,an electronic paper display device comprising an electrophoretic elementor the like, a display device employing micro-electromechanical systems(MEMS), and a display device employing electrochromism. The presentembodiment can also be applied to a wearable display device or a variantdisplay device.

FIG. 1 is an illustration showing the configuration and the equivalentcircuit of the display device DSP of the present embodiment.

In one example, a first direction X, a second direction Y and a thirddirection Z are orthogonal to one another. However, they may cross oneanother at an angle other than 90 degrees. The first direction X and thesecond direction Y correspond to directions parallel to the main surfaceof a substrate constituting the display device DSP, and the thirddirection Z corresponds to the thickness direction of the display deviceDSP. In the present specification, a direction toward the point of anarrow indicating the third direction Z is referred to as upward (orsimply above), and a direction from the point of the arrow toward theopposite side is referred to as downward (or simply below).

The display device DSP comprises a display panel PNL and a wiring boardWB mounted on the display panel PNL. The display panel PNL is a liquidcrystal display panel, and comprises a first substrate SUB1, a secondsubstrate SUB2 opposed to the first substrate SUB1, a sealing member SE,a liquid crystal layer LC, a signal line S, a scanning line G, aswitching element SW, a pixel electrode PE, a common electrode CE andthe like. In addition, the display panel PNL comprises a display area DAwhich displays an image and a non-display area NDA which surrounds thedisplay area DA.

The first substrate SUB1 comprises a mounting portion MA exposed to theoutside of the second substrate SUB2. The sealing member SE is locatedin the non-display area NDA and bonds the first substrate SUB1 and thesecond substrate SUB2 together. In FIG. 1, an area in which the sealingmember SE is disposed is indicated by upward-sloping hatch lines. Thedisplay area DA is located inside surrounded by the sealing member SE.The display panel PNL comprises a plurality of pixels PX disposed in amatrix in the first direction X and the second direction Y in thedisplay area DA.

The signal line S, the scanning line G, the switching element SW, thepixel electrode PE, the common electrode CE and the liquid crystal layerLC are located in the display area DA. The signal line S extends alongthe second direction Y, and the scanning line G extends along the firstdirection X. The switching element SW is composed of, for example, athin-film transistor (TFT), and is electrically connected to thescanning line G and the signal line S. The pixel electrode PE iselectrically connected to the switching element SW. Each pixel electrodePE is opposed to the common electrode CE, and drives the liquid crystallayer LC by an electric field produced between the pixel electrode PEand the common electrode CE. A storage capacitance CS is formed, forexample, between an electrode of the same potential as the commonelectrode CE and an electrode of the same potential as the pixelelectrode PE.

The flexible wiring board WB is mounted on the mounting portion MA. Inaddition, the wiring board WB comprises a driver IC chip 2 which drivesthe display panel PNL. Note that the driver IC chip 2 may be mounted onthe mounting portion MA.

The display panel PNL of the present embodiment may be any one of atransmissive type comprising a transmissive display function ofdisplaying an image by selectively transmitting light from the rear sideof the first substrate SUB1, a reflective type comprising a reflectivedisplay function of displaying an image by selectively reflecting lightfrom the front side of the second substrate SUB2, and a transflectivetype comprising the transmissive display function and the reflectivedisplay function.

In addition, although the description of the detailed configuration ofthe display panel PNL will be omitted here, the display panel PNL maycomprise a configuration corresponding to any one of a display modeusing a lateral electric field along the main surface of a substrate, adisplay mode using a longitudinal electric field along a normal to themain surface of a substrate, a display mode using an inclined electricfield inclined in an oblique direction with respect to the main surfaceof a substrate, and a display mode using an arbitrary combination of thelateral electric field, the longitudinal electric field and the inclinedelectric field. The main surface of a substrate here is a surfaceparallel to an XY-plane defined by the first direction X and the seconddirection Y.

FIG. 2 is a cross-sectional view of the display area DA of the displaypanel PNL shown in FIG. 1. The illustrated example corresponds to anexample where the display mode using the lateral electric field isapplied to the display panel PNL.

The display device DSP comprises a first optical element OD1, a secondoptical element OD2 and an illumination device IL in addition to thedisplay panel PNL.

The first substrate SUB1 comprises an insulating substrate 10,insulating films 11 to 16, signal lines S1 and S2, metal wiring linesML1 and ML2, the common electrode CE, the pixel electrode PE, and analignment film AL1. The insulating substrate 10 is a substrate havingoptical transparency such as a glass substrate or a flexible resinsubstrate. The insulating film 11 is located on the insulating substrate10. The insulating film 12 is located on the insulating film 11. Theinsulating film 13 is located on the insulating film 12. The signallines S1 and S2 are located on the insulating film 13, and are coveredwith the insulating film 14. The metal wiring lines ML1 and ML2 arelocated on the insulating film 14, and are covered with the insulatingfilm 15. The metal wiring lines ML1 and ML2 are located directly abovethe signal lines S1 and S2, respectively. The common electrode CE islocated on the insulating film 15, and is covered with the insulatingfilm 16. The pixel electrode PE is located on the insulating film 16,and is covered with the alignment film AL1. The common electrode CE andthe pixel electrode PE are transparent electrodes formed of atransparent conductive material such as indium tin oxide (ITO) or indiumzinc oxide (IZO).

The insulating films 11 to 13 and the insulating film 16 are inorganicinsulating films formed of an inorganic insulating material such assilicon oxide, silicon nitride or silicon oxynitride, and may have asingle-layer structure or a multilayer structure. The insulating films14 and 15 are organic insulating films formed of an organic insulatingmaterial such as acrylic resin, for example.

The second substrate SUB2 comprises an insulating substrate 20, alight-shielding layer BM, a color filter CF, an overcoat layer OC, analignment film AL2 and the like. Similarly to the insulating substrate10, the insulating substrate 20 is a substrate having opticaltransparency such as a glass substrate or a resin substrate. Thelight-shielding layer BM and the color filter CF are located on a sideof the insulating substrate 20 which is opposed to the first substrateSUB1. The color filter CF is disposed at a position opposed to the pixelelectrode PE, and partially overlaps the light-shielding layer BM. Thecolor filter CF comprises a red color filter CFR, a green color filterCFG and a blue color filter CFB. The overcoat layer OC covers the colorfilter CF. The overcoat layer OC is formed of transparent resin. Thealignment film AL2 covers the overcoat layer OC. The alignment film AL1and the alignment film AL2 are formed of, for example, a materialexhibiting horizontal alignment properties.

The first substrate SUB1 and the second substrate SUB2 are disposed suchthat the alignment film AL1 and the alignment film AL2 are opposed toeach other. The first substrate SUB1 and the second substrate SUB2 arebonded by the sealing member with a predetermined cell gap in between.The liquid crystal layer LC is held between the alignment film AL1 andthe alignment film AL2. The liquid crystal layer LC comprises liquidcrystal molecules LM. The liquid crystal layer LC is composed of apositive liquid crystal material (whose dielectric anisotropy ispositive) or a negative liquid crystal material (whose dielectricanisotropy is negative).

The first optical element OD1 including a polarizer PL1 is bonded to theinsulating substrate 10. The second optical element OD2 including apolarizer PL2 is bonded to the insulating substrate 20. The firstoptical element OD1 and the second optical element OD2 may each comprisea retarder, a scattering layer, an antireflective layer and the like asneeded.

In this display panel PNL, in an off state where no electric field isformed between the pixel electrode PE and the common electrode CE, theliquid crystal molecules LM are initially aligned in a predetermineddirection between the alignment film AL1 and the alignment film AL2. Inthis off state, light emitted from the illumination device IL toward thedisplay panel PNL is absorbed by the first optical element OD1 and thesecond optical element OD2, and dark display is realized. On the otherhand, in an on state where an electric field is formed between the pixelelectrode PE and the common electrode CE, the liquid crystal moleculesLM are aligned in a direction different from the initial alignmentdirection by an electric field, and the alignment direction iscontrolled by the electric field. In this on state, a part of the lightfrom the illumination device IL is transmitted through the first opticalelement OD1 and the second optical element OD2, and light display isrealized.

FIG. 3 is a plan view showing the mounting portion MA of the displaypanel PNL. In the drawing, a direction crossing at an acute anglecounterclockwise with respect to the second direction Y is defined as adirection D1, and a direction crossing at an acute angle clockwise withrespect to the second direction Y is defined as a direction D2. An angleθ1 between the second direction Y and the direction D1 is substantiallyequal to an angle θ2 between the second direction Y and the directionD2.

The display panel PNL comprises terminals PD1 to PD9 located in themounting portion MA, terminals PD21 to PD29, alignment marks AM11 andAM12 located in the mounting portion MA, signal wiring lines SW1 to SW9connected respectively to the terminals PD1 and PD9, and signal wiringlines SW21 to SW29 connected respectively to the terminals PD21 to PD29.In addition, the signal wiring lines SW can also be referred to simplyas wiring lines SW, and wiring lines drawn from the terminals PD of themounting portion MA may be wiring lines which supply a signal fordriving the display panel PNL from the driver IC chip, and each are apower supply line or a wiring line which supplies a voltage of a fixedpotential or the like.

Furthermore, in one example, the wiring lines SW1 to SW5 are powersupply lines which supply various voltages to the display panel PNL, andthe wiring lines SW6 to SW9 are signal wiring lines which supply varioussignals to the display panel PNL. Wiring lines clustered across thealignment mark AM which will be described later can be grouped accordingto a purpose or a function.

The alignment mark AM11 is located between the terminal PD5 and theterminal PD6. The alignment mark AM12 is located between the terminalPD24 and the terminal PD25. The terminals PD1 to PD5, the alignment markAM11 and the terminals PD6 to PD9 are arranged in parallel in this orderin the first direction X. In addition, the terminals PD21 to PD24, thealignment mark AM12 and the terminals PD25 to PD29 are arranged inparallel in this order in the first direction X. The alignment mark AM11comprises an island portion I1, an island portion I2 arranged inparallel in the first direction X of the island portion I1, an islandportion I3 arranged in parallel in the second direction Y of the islandportion I1, and an island portion I4 arranged in parallel in the seconddirection Y of the island portion I2. The alignment mark AM12 comprisesan island portion I5, an island portion I6 arranged in parallel in thefirst direction X of the island portion I5, an island portion I7arranged in parallel in the second direction Y of the island portion I5,and an island portion I8 arranged in parallel in the second direction Yof the island portion I6. The island portions I1 to I8 are formed in,for example, a rectangular shape. However, they are not limited to arectangular shape but may be formed in any shape as long as they have afunction as an alignment mark.

The center position of the width along the first direction X of themounting portion MA is defined as a center line L1. The center line L1is parallel to the second direction Y. The terminals PD1 to PD9, thesignal wiring lines SW1 to SW9, and the alignment mark AM11 are locatedon the left side of the center line L1. The terminals PD21 to PD29, thesignal wiring lines SW21 to SW29, and the alignment mark AM12 arelocated on the right side of the center line L1. The alignment marksAM11 and AM12 are disposed at positions substantially symmetric withrespect to the center line L1. In addition, the signal wiring lines SW1to SW9 extend along the direction D1. The signal wiring lines SW21 toSW29 extend along the direction D2.

FIG. 4 is a plan view showing a part of the wiring board WB.

The wiring board WB comprises connection wiring lines WR1 to WR9,connection wiring lines WR21 to WR29, and alignment marks AM21 and AM22.The connection wiring lines WR1 to WR9 and the connection wiring linesWR21 to WR29 are connected to the driver IC chip 2. In addition, theconnection wiring lines WR can also be referred to simply as wiringlines WR but are referred to as connection wiring lines in the presentspecification simply because the wiring lines WR of the wiring board WBare connected to the display panel PNL.

The alignment mark AM21 is located between the connection wiring lineWR5 and the connection wiring line WR6. The alignment mark AM22 islocated between the connection wiring line WR24 and the connectionwiring line WR25. In addition, the connection wiring lines WR1 to WR5,the alignment mark AM21, and the connection wiring lines WR6 to WR9 arearranged in parallel in this order in the first direction X. Theconnection wiring lines WR21 to WR24, the alignment mark AM22, and theconnection wiring lines WR25 to WR29 are arranged in parallel in thisorder in the first direction X. The alignment mark AM21 is formed in across shape comprising an extension portion EP1 extending in the firstdirection X and an extension portion EP2 extending in the seconddirection Y. The alignment mark AM22 is formed in a cross shapecomprising an extension portion EP3 extending in the first direction Xand an extension portion EP4 extending in the second direction Y. Inaddition, the alignment marks of the wiring board WB are not limited toa cross shape but may be formed in any shape as long as they have afunction as an alignment mark.

The center position of the width in the first direction X of the wiringboard WB is defined as a center line L2. The center line L2 is parallelto the second direction Y. The connection wiring lines WR1 to WR9 andthe alignment mark AM21 are located on the left side of the center lineL2. The connection wiring lines WR21 to WR29 and the alignment mark AM22are located on the right side of the center line L2. The alignment marksAM21 and AM22 are disposed at positions substantially symmetric withrespect to the center line L2. In addition, the connection wiring linesWR1 to WR9 extend along the direction D1. The connection wiring linesWR21 to WR29 extend along the direction D2.

The connection wiring lines WR1 to WR9 and WR21 to WR29, and thealignment marks AM21 to AM22 are formed of, for example, a metal filmsuch as copper, and the surface of the metal film is plated with tin orthe like.

FIG. 5 is a plan view showing a state where the wiring board WB shown inFIG. 4 is mounted on the mounting portion MA shown in FIG. 3. The centerline L1 of the mounting portion MA and the center line L2 of the wiringboard WB overlap each other.

The connection wiring lines WR1 to WR9 of the wiring board WB areconnected to the terminals PD1 to PD9 of the mounting portion MA,respectively. The connection wiring lines WR21 to WR29 of the wiringboard WB are connected to the terminals PD21 to PD29 of the mountingportion MA, respectively.

The alignment marks AM11 and AM21 are arranged in parallel in the seconddirection Y. In addition, the alignment marks AM12 and AM22 are arrangedin parallel in the second direction Y. The signal wiring lines SW1 toSW9 and the connection wiring lines WR1 to WR9 located on the left sideof the center line L1 extend along the direction D1. Therefore, a centerpoint O11 of the alignment mark AM11 and a center point O21 of thealignment mark AM21 are arranged in parallel along the direction D1.That is, the center point O21 is located on the center line L1 side ofthe center point O11. The island portions I2 and I4 and the extensionportion EP2 are arranged in the second direction Y. In addition, thesignal wiring lines SW21 to SW29 and the connection wiring lines WR21 toWR29 located on the right side of the center line L1 extend along thedirection D2. Therefore, a center point O12 of the alignment mark AM12and a center point O22 of the alignment mark AM22 are arranged inparallel along the direction D2. That is, the center point O22 islocated on the center line L1 side of the center point O12. The islandportions I5 and I7 and the extension portion EP4 are arranged in thesecond direction Y. The alignment marks are used for aligning thedisplay panel PNL and the wiring board WB when they are connectedtogether. They are aligned when the positions of the alignment marks ofthem reach predetermined values.

The number of signal wiring lines and the number of connection wiringlines disposed on the right side and the left side of the alignmentmarks are not limited. Only at least one set of a signal wiring line anda connection wiring line has to be positioned on the left side of thealignment marks AM11 and AM21. Similarly, only at least one set of asignal wiring line and a connection wiring line has to be positioned onthe right side of the alignment marks AM12 and AM22. Furthermore, in theillustrated example, the center point of the alignment mark of thedisplay panel PNL and the center point of the alignment mark of thewiring board WB are offset from each other. However, the center pointO11 of the alignment mark AM11 and the center point O21 of the alignmentmark AM21 may overlap each other, and the center point O12 of thealignment mark AM12 and the center point O22 of the alignment mark AM22may overlap each other.

FIG. 6 is a cross-sectional view of the display device DSP along thesignal wiring line SW1 and the connection wiring line WR1 shown in FIG.5. That is, FIG. 6 is a plan view along a plane defined by the thirddirection Z and the direction D1.

The signal wiring line SW1 is located between the insulating film 12 andthe insulating film 13. The signal wiring line SW1 is located in thesame layer as the scanning line G shown in FIG. 1 and is formed of thesame material as the scanning line G. The signal wiring line SW1 and thescanning line G are formed of a metal material such as aluminum (Al),titanium (Ti), silver (Ag), molybdenum (Mo), tungsten (W), copper (Cu)or chromium (Cr), an alloy of these metal materials combined together orthe like, and may have a single-layer structure or a multilayerstructure. In one example, the signal wiring line SW1 and the scanningline G are formed of a molybdenum tungsten alloy. The alignment marksAM11 and AM12 shown in FIG. 5 are located in the same layer as thesignal wiring line SW1, and are formed of the same material as thesignal wiring line SW1 and the scanning line G.

The terminal PD1 is composed of metal layers MEL1 and MEL2 andtransparent conductive layers TL1 and TL2. The metal layer MEL1 islocated between the insulating film 13 and the insulating film 14, andis in contact with the signal wiring line SW1 via a contact hole of theinsulating film 13. The metal layer MEL1 is located in the same layerand formed of the same material as the signal lines S1 and S2 shown inFIG. 2. The metal layer MEL1 and the signal lines S1 and S2 are formedof any one of the above-described metal materials, an alloy of theabove-described metal materials combined together or the like, and mayhave a single-layer structure or a multilayer structure. In one example,the metal layer MEL1 and the signal lines S1 and S2 are formed of alayer stack of the first layer containing titanium (Ti), the secondlayer containing aluminum (Al) and the third layer containing titanium(Ti) stacked in this order.

The metal layer MEL2 is located between the insulating film 14 and theinsulating film 15, and is in contact with the metal layer MEL1 via acontact hole of the insulating film 14. The metal layer MEL2 is locatedin the same layer and formed of the same material as the metal wiringlines ML1 and ML2 shown in FIG. 2. The metal layer MEL2 and the metalwiring lines ML1 and ML2 are formed of any one of the above-describedmetal materials, an alloy of the above-described metal materialscombined together or the like, and may have a single-layer structure ora multilayer structure. In one example, the metal layers MEL2 and themetal wiring lines ML1 and ML2 each are a layer stack of the first layercontaining titanium (Ti), the second layer containing aluminum (Al) andthe third layer containing titanium (Ti) stacked in this order, or alayer stack of the first layer containing molybdenum (Mo), the secondlayer containing aluminum (Al) and the third layer containing molybdenum(Mo) stacked in this order.

The transparent conductive layer TL1 is located between the insulatingfilm 15 and the insulating film 16, and is in contact with the metallayer MEL2 via a contact hole of the insulating film 15. The transparentconductive layer TL1 is located in the same layer and formed of the samematerial as the common electrode CE shown in FIG. 2. The transparentconductive film TL2 is located on the insulating film 16 and is incontact with the transparent conductive film TL1 via a contact hole ofthe insulating film 16. The transparent conductive film TL2 is locatedin the same layer and formed of the same material as the pixel electrodePE shown in FIG. 2.

The wiring board WB comprises an insulating substrate 30, the connectionwiring line WR1, and a solder resist SR covering the connection wiringline WR1. The insulating substrate 30 comprises an upper surface 30 aand a lower surface 30 b. The insulating substrate 30 is formed of, forexample, polyimide. The connection wiring line WR1 is located on thelower surface 30 b of the insulating substrate 30. The solder resistorSR does not extend to a position opposed to the terminal PD1 of thedisplay panel PNL but exposes the connection wiring line WR1 at theposition opposed to the terminal PD1. The wiring board WB iselectrically connected and bonded to the display panel PNL by ananisotropic conductive film 3 which is a conductive material. That is,the anisotropic conductive film 3 is interposed between the firstsubstrate SUB1 and the wiring board WB. The wiring board WB and thedisplay panel PNL are electrically and physically connected together bypressing them from above and below in the third direction Z with theanisotropic conductive film 3 interposed and heating them.

The anisotropic conductive film 3 connects the terminals PD1 to PD5 andthe connection wiring lines WR1 to WR5, the terminals PD6 to PD9 and theconnection wiring lines WR6 to WR9, the terminals PD21 to PD24 and theconnection wiring lines WR21 to WR24, and the terminals PD25 to PD29 andthe connection wiring lines WR25 to WR29 shown in FIG. 5.

FIG. 7 is a cross-sectional view showing a process of mounting thewiring board WB on the display panel PNL.

The display panel PNL is disposed on a stage ST. As shown in FIGS. 8 and9, the wiring board WB is attracted to a suction device 100. The suctiondevice 100 comprises a space inside, and turns the space into a vacuumand attracts the wiring board WB. The suction device 100 attracts theupper surface 30 a of the insulating substrate 30. The alignment markAM21 of the wiring board WB is located on the lower surface 30 b side ofthe insulating substrate 30.

The mounting of the wiring board WB on the display panel PNL takes thefollowing procedure. Light LT is emitted from below the display panelPNL, and an image is captured from below the display panel PNL by acamera for recognizing the alignment marks. A manufacturing devicerecognizes the position of the alignment mark of the display panel PNLand the position of the alignment mark of the wiring board WB, andaligns the display panel PNL and the wiring board WB. Then, the displaypanel PNL and the wiring board WB are bonded with the anisotropicconductive film interposed by thermocompression bonding.

FIG. 8 is a plan view showing the wiring board WB and the suction device100 shown in FIG. 7. FIG. 8 is a plan view from above the suction device100 shown in FIG. 7.

The suction device 100 comprises suction ports SH1 to SH4 arranged inthe first direction X. In the illustrated example, the suction port SH1overlaps the connection wiring lines WR1 to WR4, the suction port SH2overlaps the connection wiring lines WR6 to WR13, the suction port SH3overlaps the connection wiring lines WR17 to WR24, and the suction portSH4 overlaps the connection wiring line WR25 to WR29. The alignment markAM21 is located between the suction port SH1 and the suction port SH2.The alignment mark AM22 is located between the suction port SH3 and thesuction port SH4. As described above, the suction device 100 attractsthe wiring board WB such that the suction ports are located on the rightside and the left side of the alignment mark. The suction device 100sucks both sides of the alignment mark AM21 and both sides of thealignment mark AM22. The suction device 100 comprises suction ports (notshown) also between the suction port SH2 and the suction port SH3. Thedisplay panel PNL and the wiring board WB are aligned by the alignmentmarks AM11 and AM21 and aligned by the alignment marks AM12 and AM22 asshown in FIG. 5. At this time, the alignment marks AM11 and AM21 do notoverlap each other, and the alignment marks AM12 and AM22 do not overlapeach other.

FIG. 9 is a cross-sectional view showing the wiring board WB and thesuction device 100 along line A-B shown in FIG. 8.

The suction device 100 comprises a space SP inside. The space SPcommunicates with the suction ports SH1 to SH4. The suction ports SH1 toSH4 are hermetically closed by the upper surface 30 a of the insulatingsubstrate 30.

The wiring board WB tends to roll up under no external force. Since thesuction ports SH1 and SH2 attract areas on the right side and the leftside of the alignment mark AM21, a part of the wiring board WB in whichthe alignment mark AM21 is located can be maintained flat. Similarly,since the suction ports SH3 and SH4 attract areas on the right side andthe left side of the alignment marks AM22, a part of the wiring board WBin which the alignment mark AM22 is located can be maintained flat.

FIG. 10 is a plan view showing a comparison on the positions of thealignment marks AM11 and AM12 between a comparative example and thepresent embodiment. FIG. 10 (a) is a plan view showing the comparativeexample, and FIG. 10 (b) is a plan view showing the present embodiment.In FIG. 10, the configuration on the left side of the center line L1 isillustrated. Since the configuration on the right side of the centerline L1 is similar to this configuration, description will be omitted.

In the comparative example shown in FIG. 10 (a), the alignment marksAM11 and AM2 l are located more outward than the signal wiring line SW1and the connection wiring line WR1. In order to position the suctionports of the suction device on the right side and the left side of thealignment mark AM21, it is necessary to secure a suction area forpositioning the suction port on the left side of the alignment markAM21. The suction area AR corresponds to an area indicated by hatchlines in the drawing. For example, in the comparative example, the widthin the first direction X of the suction area AR is about greater than orequal to 0.65 mm.

According to the present embodiment, as shown in FIG. 10 (b), thealignment marks AM11 and AM21 are located between the signal wiring lineSW5 and the connection wiring line WR5 and the signal wiring line SW6and the connection wiring line WR6. Therefore, the suction area ARoverlaps the connection wiring lines WR1 to WR5. That is, the suctionarea AR and the area for disposing the connection wiring lines WR1 toWR5 can be combined. Therefore, the distance from the center line L1 toan edge portion EG of the wiring board WB can be reduced as comparedwith the comparative example. For example, the distance from the edgeportion EG of the wiring board WB to the center line L1 can be reducedby about 0.35 mm as compared with the comparative example. In addition,for example, also in the present embodiment, the width in the firstdirection X of the suction area AR is about greater than or equal toabout 0.65 mm. As described above, it is possible to reduce the width ofthe wiring board WB without reducing the suction area AR. Furthermore,since the width of the wiring substrate WB can be reduced, the wiringboard WB fit for the miniaturization of the display panel PNL can bemanufactured.

Furthermore, the connection wiring line WR1 can be located close to theedge portion EG, and the area for disposing the connection wiring linesWR can be increased. Therefore, the number of connection wiring lines WRcan be increased or the pitch of the connection wiring lines WR can beincreased. Furthermore, when the pitch is increased, the width of theconnection wiring lines WR can be increased, and the resistance can bereduced. When the number, the pitch and the width of the connectionwiring lines WR are increased, the number, the pitch and the width ofthe signal wiring lines SW of the display panel PNL can be increased,accordingly. Furthermore, when the pitch and the width of the signalwiring lines SW and the pitch and the width of the connection wiringlines WR are increased, the risk of the misalignment of the displaypanel PNL and the wiring board WB can be reduced. Note that it is alsopossible to increase the area for disposing the connection wiring linesWR without reducing the width of the wiring board WB.

FIG. 11 is a plan view showing a comparison on the mounting portion MAbetween a comparative example and the present embodiment. FIG. 11 (a) isa plan view showing the comparative example, and FIG. 11 (b) is a planview showing the present embodiment.

The display device DSP comprises barcodes BC1 and BC2 located in themounting portion MA and test terminals TT1 and TT2 located in themounting portion MA. In the example shown in FIG. 11 (a), the barcodeBC1 and the test terminal TT1 are arranged in the second direction Y onthe left side of the wiring board WB, and the barcode BC2 and the testterminal TT2 are arranged in the second direction Y on the right side ofthe wiring board WB. The wiring board WB has a width W11 in the firstdirection X. In addition, the mounting portion MA has a width W1 in thesecond direction Y.

As shown in FIG. 11 (b), in the present embodiment, the wiring board WBhas a width W12 in the first direction X, and the width W12 is less thanthe width W11. Therefore, areas on the right side and the left side ofthe wiring board WB can be expanded as compared with the comparativeexample. That is, the barcode BC1 and the test terminal TT1 can bearranged in the first direction X on the left side of the wiring boardWB, and the barcode BC2 and the test terminal TT2 can be arranged in thefirst direction X on the right side of the wiring board WB. Therefore,the width W2 in the second direction Y of the mounting portion MA can bemade less than the width W1 of the comparative example. In theillustrated example, the barcode and the test terminal are taken as anexample. However, the elements are not limited to them but may be othermembers.

In addition, since the areas on the right side and the left side of thewiring board WB can be expanded in the mounting portion MA, thecurvatures of corner portions CN1 and CN2 of the display panel PNL canbe expanded. That is, the desired corner portions CN1 and CN2 accordingto the requested shape of the display device can be formed. Furthermore,since the connection wiring lines WR of the wiring board WB can belocated more outward, an area for drawing signal wiring lines to beconnected can be reduced, and the non-display area NDA on the mountingportion MA side can be reduced.

FIG. 12 is a plan view showing the first modification example of thepresent embodiment. The configuration shown in FIG. 12 is different fromthe configuration shown in FIG. 10 (b) in that dummy terminals DM1 toDM10 are disposed.

The wiring board WB comprises dummy terminals DM1 to DM5 overlapping thealignment mark AM11, and dummy terminals DM6 to DM10 located on anopposite side to the dummy terminals DM1 to DM5 with respect to thealignment mark AM21. The dummy terminals DM1 to DM10 are located betweenthe connection wiring line WR5 and the connection wiring line WR6 andextend along the direction D1. The dummy terminals DM6 to DM10 do notoverlap the alignment mark AM11. By disposing the dummy terminals DM1 toDM10, the layer thickness of the wiring board WB can be made uniform. Inparticular, the layer thickness of the wiring board WB is made uniformin portions overlapping the terminals PD and the alignment mark AM11,and the display panel PNL and the wiring board WB can be compressed andbonded by the anisotropic conductive film more easily.

Effects similar to those produced in the above-described embodiment canalso be produced in the first modification example.

FIG. 13 is a plan view showing the second modification example of thepresent embodiment. The configuration of FIG. 13 is different from theconfiguration shown in FIG. 10 (b) in that the signal wiring lines SW1to SW9, the terminals PD1 to PD9, and the connection wiring lines WR1 toWR9 extend along the second direction Y.

The center point O11 of the alignment mark AM11 and the center point O21of the alignment mark AM21 are arranged in parallel along the seconddirection Y. The alignment mark AM11 comprises a gap GP along the seconddirection Y between the island portions I1 and I3 and the islandportions I2 and I4. The gap GP and the extension portion EP2 of thealignment mark AM21 are arranged in the second direction Y.

Effects similar to those produced in the above-described embodiment canalso be produced in the second modification example.

As described above, according to the present embodiment, a displaydevice, a display panel and a wiring board which can achieveminiaturization can be obtained.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A display device comprising: a display panelcomprising a first substrate; and a wiring board mounted on a mountingportion of the first substrate, wherein the display panel comprises afirst terminal and a second terminal located in the mounting portion, afirst alignment mark located in the mounting portion and located betweenthe first terminal and the second terminal, a first wiring lineconnected to the first terminal, and a second wiring line connected tothe second terminal, and the wiring board comprises a first connectionwiring line connected to the first terminal, a second connection wiringline connected to the second terminal, and a second alignment marklocated between the first connection wiring line and the secondconnection wiring line, the first terminal, the first alignment mark,and the second terminal are arranged in parallel in a first direction,the first connection wiring line, the second alignment mark, and thesecond connection wiring line are arranged in parallel in the firstdirection, the first alignment mark and the second alignment mark arearranged in parallel in a second direction crossing the first direction,the wiring board further comprises a first dummy terminal overlappingthe first alignment mark, and a second dummy terminal located on anopposite side to the first dummy terminal with respect to the secondalignment mark, and the first dummy terminal and the second dummyterminal are located between the first connection wiring line and thesecond connection wiring line.
 2. The display device of claim 1, whereinthe wiring board comprises a driver IC chip which drives the displaypanel, and the first connection wiring line and the second connectionwiring line are connected to the driver IC chip.
 3. The display deviceof claim 1, wherein the first terminal, the second terminal, the firstconnection wiring line, and the second connection wiring line areinclined with respect to the second direction, and a center of thesecond alignment mark is located on a side on which a center of a widthin the first direction of the wiring board is located with respect to acenter of the first alignment mark.
 4. The display device of claim 1,wherein the first alignment mark comprises a first island portion, asecond island portion arranged in parallel in a first direction of thefirst island portion, a third island portion arranged in parallel in asecond direction crossing the first direction of the first islandportion, and a fourth island portion arranged in parallel in the seconddirection of the second island portion, and the second alignment mark isformed in a cross shape comprising a first extension portion extendingin the first direction and a second extension portion extending in thesecond direction.
 5. The display device of claim 1, wherein a barcode, atest terminal and the wiring board are arranged in parallel in a firstdirection.
 6. The display device of claim 1, wherein the display panelfurther comprises a third terminal and a fourth terminal located in themounting portion, a third alignment mark located in the mounting portionand located between the third terminal and the fourth terminal, a thirdwiring line connected to the third terminal, and a fourth wiring lineconnected to the fourth terminal, and the wiring board comprises a thirdconnection wiring line connected to the third terminal, a fourthconnection wiring line connected to the fourth terminal, and a fourthalignment mark located between the third connection wiring line and thefourth connection wiring line.